1. Field of the Invention
The invention relates to the technical field of quality of service (QoS) control in communication and, more particularly, to a system and method for controlling multimedia communication quality in a handheld device.
2. Description of Related Art
Wireless communication systems gradually change from analog wireless communication systems, such as Advanced Mobile Phone System (AMPS), and Total Access Communication System (TACS), to digital wireless communication systems, such as Global System for Mobile Communications (GSM), Code Division Multiple Access (CDMA)), and Time Division Multiple Access (TDMA). The first-generation and the second-generation wireless communication systems are replaced gradually by the third-generation wireless communication systems. The first-generation wireless communication systems essentially provide voice services. In addition to the voice services, the second-generation wireless communication systems essentially provide data communications. The third-generation (3G) wireless communication systems essentially provide various contents such as multimedia and video messages. In the 3G systems, the Wideband CDMA (WCDMA) systems have the capability of high-speed wireless linking and accordingly are considered as a platform of new applications such as a videoconference.
The videoconference is considered as a killer application of driving the 3G wireless communication affairs. US publication 2005/0265383 entitled “Method and system for Communicating Video Data in a Packet-Switched Network, Related Network and Computer Program Product Therefor” has disclosed sending video data in a radio channel of a packet-switched network. However, due to the packet-switched network, it cannot provide a quality of service (QoS) guarantee. Namely, the video quality sent in such a packet-switched network cannot be ensured.
Currently, only the circuit-switched protocol, i.e., 3G-234m, can provide a possible solution for carrying out a videoconference of wireless network. However, the conventional video coding (such as H.263) typically uses a fixed output stream bit-rate and fixed coding parameters, which is not suitable for a radio channel due to noise interference and limited bandwidth. In addition, the 3G-324m protocol does not provide the mechanism of video QoS guarantee. Hence, it is desired to have a technical improvement on the prior videoconference of wireless network.